In a large bowl, combine soy sauce, honey, ketchup, garlic, basil, oregano, red pepper flakes, and pepper.
Place chicken thighs, potatoes, carrots, and soy sauce mixture into a 6-qt slow cooker. Cover and cook on low heat for 7-8 hours or high for 3-4 hours, basting every hour. Add green beans during the last 30 minutes of cooking time.
OPTIONAL: Preheat oven to broil. Place chicken thighs onto a baking sheet, skin side up, and broil until crisp, about 3-4 minutes.
Serve chicken immediately with potatoes, carrots, and green beans, garnished with parsley, if desired.